1. Field of the Invention
This invention relates to a ball joint for an automobile stabilizer, more particularly for connecting a stabilizer rotatably installed on the body of an automobile, to a suspension arm.
The purpose of the automobile stabilizer is to increase the traveling stability of the automobile by creating a resistant force against a rolling motion of the automobile body such as due to sharp turning of the automobile. To reduce the rolling motion of the automobile body, the stabilizer has a U-shaped torsion bar spring installed between the suspension arm and the automobile body to compensate for vertical vibration. Generally, the center part of the U-shape bar is used as the torsion bar spring, the center part being rotatably connected to the automobile body via a rubber cushion or rubber bush. Each end of the U-shaped bar is connected to a suspension arm through a ball joint.
2. Description of the Related Art
Referring to FIG. 11, there is shown an example of a ball joint for connecting each end of the arm of the stabilizer with a suspension arm. The ball joint consists of two metal sockets 3 which include synthetic resin ball seats 2 inside for rotatably holding ball heads 1a of ball studs 1, and a connecting rod 4 which connects both sockets 3 together. One ball stud of this ball joint is installed on one end of a stabilizer arm and the other ball stud of this ball joint is connected to a suspension arm to transmit the input from a wheel to the stabilizer.
However, the type of the ball joint explained above suffers from a number of deficiencies. For example, the ball joint sockets need to be fixed to the connecting rod 4 by welding, thus requiring additional manufacturing time and expense. In addition, the ball joint is rather heavy because it is made of metal, thus affecting the overall weight of the automobile in which it is installed. U.S. Pat. No. 4,260,275, U.S. Pat. No. 4,283,833, and GB Patent No. 1,302,871 are examples of welded-types of ball joints.